I usually draw a blank when people ask me to offer a possible upset or two. After all, I’d rather not be surprised on election night, though there are almost always a couple of unexpected outcomes.

But I’ve been looking at some numbers recently and have been struck by a handful of races that I assumed I wouldn’t be watching at this point but that are now intriguing. The favored candidate may well win the election (these are only possible upsets, after all), but at the very least, these races seem worth watching.

California’s 9th

The idea that Rep. Jerry McNerney (D) would lose to challenger Ricky Gill (R) always struck me as little more than wishful thinking by Republicans. Gill, after all, is a 25-year-old Indian-American law school graduate making his first run for office. True, Gill raised almost $1 million in the off-year and GOP strategists have been promoting his candidacy since last year, but McNerney, who ousted incumbent Rep. Richard Pombo (R) in 2006, has proved to be more adept than Republicans ever believed.

But insiders on both sides of the aisle agree that Gill has become a serious threat to McNerney. Democrats are scratching their heads in disbelief over the development, while Republicans are simply happy with the situation. Redistricting moved the district farther east, and President George W. Bush carried the redrawn district narrowly in 2004. Because of that, the idea of a Gill upset of the Congressman is not delusional, but it isn’t something that many believed was truly possible.

California’s 36th

If Democrats are worried about McNerney, some Republicans are nervous about Rep. Mary Bono Mack, an eight-term Republican from Palm Springs who finds herself with a serious challenge from Harvard University-educated physician Raul Ruiz (D), the son of migrant workers.

Democrats have been hammering the Republican on the usual issues, including Medicare and the House GOP budget spearheaded by Rep. Paul Ryan (Wis.), and the district’s growing Hispanic population is a long-term problem for the Republican Congresswoman. While most of the polling in the race still shows Bono Mack ahead, this district is getting more attention from insiders of both parties than I initially expected.

Nevada’s 4th

This new district was expected to elect a Democrat, but Republican Danny Tarkanian has been able to hold onto a lead over state Senate Majority Leader Steve Horsford (D).

Tarkanian’s father, Jerry, had a colorful and controversial career as head coach of the University of Nevada-Las Vegas men’s basketball team, including a national championship in 1990. But he was forced out by the university’s president after the 1992 season, ultimately continuing his coaching career at Fresno State. Danny joined his father in California but eventually returned to Nevada, where he ran unsuccessfully for a number of offices. He lost general election races for the state Senate and secretary of state and a primary for the GOP U.S. Senate nomination in 2010.

But Danny Tarkanian has name recognition, including from his father, his mother, Las Vegas City Councilwoman Lois Tarkanian (D), and his own previous campaigns. And he has made ethics a major issue against Horsford. All of that seems to have combined to give him a chance in a race most decided was a foregone conclusion after Democrats recruited Horsford.

Arizona’s 9th

This metro Phoenix-based district was tailor-made for a Democrat, and state Sen. Kyrsten Sinema (D) may still win it next month. But things aren’t proving to be so easy for Democrats. Republican Vernon Parker, a conservative African-American who was mayor of Paradise Valley, is turning out to be a strong candidate, and polling shows this race much closer than most anticipated.

The Democratic Congressional Campaign Committee has run ads painting Parker as a tea party extremist, while the National Republican Congressional Committee has run ads that point to Sinema’s past statements and issue positions to argue that she is the extremist. Parker has to be regarded as an underdog given the fundamental partisan bent of district voters, but polling suggests he is very much still in this race.

A few other contests are worth mentioning. The race in Arizona’s 1st district isn’t going easily for former Rep. Ann Kirkpatrick (D), as most expected. Former state Sen. Jonathan Paton, an Iraq War veteran, looked to have plenty of baggage — Democrats refer to him as “Payday” Paton because he worked for the payday loan industry — but so far Kirkpatrick hasn’t been able to open a lead in this race.

Two weeks ago, I probably would have put challenger Val Demings (D) in this column. But there are now so many GOP surveys showing Rep. Daniel Webster in pretty good shape that I left the race in Florida’s 10th district off the list.

I also left the Pennsylvania Senate race off because I’m skeptical about the “independent” polls that show Tom Smith (R) just a couple of points behind Sen. Bob Casey (D) in that contest.

Some folks (Democrats and Republicans) might put Rep. Dave Loebsack (D) in Iowa’s 2nd on the list, and his race bears watching. But what I’ve seen so far in polling doesn’t currently justify putting challenger John Archer (R) on the list of potential upset winners.